diff --git a/src/main/index.ts b/src/main/index.ts
index fc3b1dd..06e4a99 100644
--- a/src/main/index.ts
+++ b/src/main/index.ts
@@ -20,7 +20,7 @@ import { TaskBoard } from './task-board'
 import { buildTree } from './tree'
 import { UpdateService } from './update-service'
 import type { CtxDeps, GitFetchOptions, ShellResult } from './workflow-ctx'
-import { discoverWorkflows, loadWorkflow } from './workflow-loader'
+import { discoverWorkflows, esbuildBinaryPath, loadWorkflow } from './workflow-loader'
 import { WorkflowManager } from './workflow-manager'
 import { WorkflowRunStore } from './workflow-run-store'
 import { scaffoldWorkflow } from './workflow-scaffold'
@@ -30,6 +30,18 @@ import { WorkspaceRegistry } from './workspace-registry'
 
 const execFileAsync = promisify(execFile)
 
+// The workflow-loader bundles workflow.ts with esbuild, which spawns its native
+// binary. In a packaged app esbuild resolves that binary to a path inside
+// app.asar (not a real file → spawn ENOENT); point its env at the unpacked copy
+// before the first build(). No-op in dev, where the binary sits in node_modules.
+if (app.isPackaged && !process.env.ESBUILD_BINARY_PATH) {
+  process.env.ESBUILD_BINARY_PATH = esbuildBinaryPath(
+    process.resourcesPath,
+    process.platform,
+    process.arch
+  )
+}
+
 /**
  * WF2 real `ctx.git.fetch` (WF2-07): a no-shell `git fetch`, mirroring the
  * worktree-manager `git` seam. `GIT_TERMINAL_PROMPT=0` fails fast instead of
diff --git a/src/main/workflow-loader.test.ts b/src/main/workflow-loader.test.ts
index 0768e84..5b039a9 100644
--- a/src/main/workflow-loader.test.ts
+++ b/src/main/workflow-loader.test.ts
@@ -2,7 +2,7 @@ import { mkdirSync, mkdtempSync, readdirSync, rmSync, writeFileSync } from 'node
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { afterEach, describe, expect, it } from 'vitest'
-import { discoverWorkflows, loadWorkflow, validateMeta } from './workflow-loader'
+import { discoverWorkflows, esbuildBinaryPath, loadWorkflow, validateMeta } from './workflow-loader'
 
 const dirs: string[] = []
 afterEach(() => {
@@ -22,6 +22,37 @@ function workflowDir(files: Record<string, string>): string {
   return folder
 }
 
+describe('esbuildBinaryPath (pure)', () => {
+  it('points at the unpacked win32 .exe under app.asar.unpacked', () => {
+    const p = esbuildBinaryPath('C:\\app\\resources', 'win32', 'x64')
+    expect(p).toBe(
+      join(
+        'C:\\app\\resources',
+        'app.asar.unpacked',
+        'node_modules',
+        '@esbuild',
+        'win32-x64',
+        'esbuild.exe'
+      )
+    )
+  })
+
+  it('uses the bin/esbuild layout on non-Windows platforms', () => {
+    const p = esbuildBinaryPath('/app/resources', 'darwin', 'arm64')
+    expect(p).toBe(
+      join(
+        '/app/resources',
+        'app.asar.unpacked',
+        'node_modules',
+        '@esbuild',
+        'darwin-arm64',
+        'bin',
+        'esbuild'
+      )
+    )
+  })
+})
+
 describe('validateMeta (pure)', () => {
   const run = async (): Promise<void> => {}
 
diff --git a/src/main/workflow-loader.ts b/src/main/workflow-loader.ts
index 7005f85..0961b9b 100644
--- a/src/main/workflow-loader.ts
+++ b/src/main/workflow-loader.ts
@@ -17,6 +17,30 @@ export type LoadedWorkflow = { meta: WorkflowMeta; run: RunFn } | { error: strin
 /** Node builtins + electron are left external — a bundled workflow never inlines them. */
 const EXTERNAL = [...builtinModules, ...builtinModules.map((m) => `node:${m}`), 'electron']
 
+/**
+ * The on-disk path of esbuild's native binary inside a packaged app (WF fix).
+ * esbuild resolves its binary relative to its own package, which electron-builder
+ * places inside `app.asar`; a `.exe` there is not a real file, so `spawn` gets
+ * ENOENT. electron-builder DOES smart-unpack `@esbuild/*` to `app.asar.unpacked`,
+ * so we point esbuild's `ESBUILD_BINARY_PATH` env at that real copy. Pure so it
+ * can be unit-tested without Electron; the caller supplies `process.resourcesPath`.
+ */
+export function esbuildBinaryPath(
+  resourcesPath: string,
+  platform: NodeJS.Platform,
+  arch: string
+): string {
+  const bin = platform === 'win32' ? 'esbuild.exe' : join('bin', 'esbuild')
+  return join(
+    resourcesPath,
+    'app.asar.unpacked',
+    'node_modules',
+    '@esbuild',
+    `${platform}-${arch}`,
+    bin
+  )
+}
+
 /**
  * List the workflow folder names directly under `root` (workflow id = folder
  * name, WF2-01). Returns `[]` — never throws — when `root` is missing or empty.